Search found 902 matches
- Wed May 21, 2014 10:19 pm
- Forum: Telescopes and instruments
- Topic: Laser pointers
- Replies: 15
- Views: 7139
Re: Laser pointers
If a laser is mounted as a piece of scientific equipment - ie not hand held - then different rules apply. At a certain establishment in Berkshire they use lasers to initiate nuclear fusion - they are a bit more powerful than 1 mW!! Mounted on your telescope may appear to be covered by this proviso. ...
- Wed May 21, 2014 10:03 pm
- Forum: Telescopes and instruments
- Topic: DMK21 Mono Imaging Camera & PST
- Replies: 2
- Views: 2066
Re: DMK21 Mono Imaging Camera & PST
I have a PST which I double-stack - I have been wanting to get a DMK21, your results have inspired me enormously - thanks!!
- Wed May 21, 2014 9:58 pm
- Forum: Light pollution
- Topic: DIY Turn off your local street light ?
- Replies: 14
- Views: 13483
Re: DIY Turn off your local street light ?
Us solar observers just laugh at light pollution!!
- Sun May 05, 2013 9:26 pm
- Forum: General chat
- Topic: Climate Change - Global Warming CC-GW PART 1
- Replies: 46
- Views: 7580
Re: Climate Change - Global Warming CC-GW PART 1
Yes water vapour is quite gaseous.brian livesey wrote: I'm no expert, but is water vapour really a "gas"?
- Sun Apr 14, 2013 11:22 am
- Forum: General chat
- Topic: Climate Change - Global Warming CC-GW PART 1
- Replies: 46
- Views: 7580
Re: Climate Change - Global Warming CC-GW PART 1
Whenever I meet a global warming panicker, I always ask what is the most important greenhouse gas?! None of them have got it right yet.
- Thu Mar 28, 2013 2:48 pm
- Forum: General chat
- Topic: Climate Change - Global Warming CC-GW PART 1
- Replies: 46
- Views: 7580
Re: Climate Change - Global Warming CC-GW PART 1
As no one here seems to have any idea - the MOST IMPORTANT greenhouse gas is WATER VAPOUR. Because of the water vapour in the atmosphere, the Earth´s mean temperature is maintained PRESENTLY at +15C. Take out the water vapour and it drops to -15C - which has happened in the past - when the entire pl...
- Thu Mar 28, 2013 2:40 pm
- Forum: General chat
- Topic: What future for casual astronomy?
- Replies: 33
- Views: 7991
Re: What future for casual astronomy?
You do realise that Betamax is technically the best system!peteuplink wrote: Took me ages to convert from VHS to DVD
- Tue Mar 26, 2013 6:13 pm
- Forum: General chat
- Topic: Climate Change - Global Warming CC-GW PART 1
- Replies: 46
- Views: 7580
Re: Climate Change - Global Warming CC-GW PART 1
Ever since the earth formed its climate has ALWAYS been changing. The question is what is causing this change - is it anything at all to do with CO2 levels or do changes in CO2 levels actually follow changes in climate rather than cause them, as some climatologists believe to be the case. And what i...
- Sun Mar 17, 2013 5:47 pm
- Forum: General chat
- Topic: What future for casual astronomy?
- Replies: 33
- Views: 7991
Re: What future for casual astronomy?
Betamax FOR EVER !!!!!peteuplink wrote:Took me ages to convert from VHS to DVD
- Sun Mar 03, 2013 7:47 pm
- Forum: Absolute beginners
- Topic: Finding the Pole Star (degrees of elevation)
- Replies: 18
- Views: 11809
Re:
Am I right in saying that 1 degree is approximately 70 miles? Depends what sort of miles you are talking about. If you start thinking about Nautical Miles it gets a lot easier (again approximately as there are slight variations) but 1 deg =(approx.) 60 Nautical miles Ian Isn´t 1 degree of latitude ...
- Sun Mar 03, 2013 7:36 pm
- Forum: General chat
- Topic: Sir Patrick Moore
- Replies: 53
- Views: 13887
Re: Sir Patrick Moore
I find the vitriol being thrown after the death of a good man all rather sad.
- Sun Mar 03, 2013 7:16 pm
- Forum: General chat
- Topic: GOTO in Theory and Practice
- Replies: 12
- Views: 2819
Re: GOTO in Theory and Practice
David Frydman wrote: make the Earth flat,
Isn´t it ??
- Mon Sep 24, 2012 12:40 am
- Forum: General chat
- Topic: Flat lenses will revolutionise optics?
- Replies: 8
- Views: 2254
Re: Flat lenses will revolutionise optics?
Didn´t ´Q´ do that with a car in one of the Bond movies?David Frydman wrote:Also at Imperial College theoretically it is possible to bend light so that an object disappears.
Albireo
I had my first view of Albireo (beta Cygni) tonight. Wow it knocked my socks off, beautiful bright, wide double, the two stars of distinctly different colours (orange and blue). Currently very close to the zenith at civilised observing times. Recommended.
- Thu Aug 30, 2012 1:44 pm
- Forum: Telescopes and instruments
- Topic: What size Threads ?
- Replies: 1
- Views: 1651
Re: What size Threads ?
This sort of thing is always a problem. Manufacturers can and do use a mix of standards. I wanted some additional screws for my Stellarvue clamshell - an email to Vic Maris got me the required info - some obscure imperial size thread. A quick google found me a supplier in the UK - only pennies each....